The restoration of the temple in Zechariah's day is a shadow of the Temple to be built in Christ's glorious day. In that time four spirits (horses similar to those described in Revelations) will be sent to and fro to accomplish the final judgments. Christ the Branch will once and for all take His rightful throne. In remembrance of this foreshadowing, the crowns given to the priest Joshua are to be kept in the restored temple.
For those who have difficulty discerning the relationship of the Father God to the Son God, perhaps it is better understood them as Trunk and Branch. Human words have deficiencies, but, individually they can be viewed as Tree, more importantly they are collectively Tree. It is perhaps easier to discern Tree seeing them both together. This is not the first time Christ has been identified as the Branch.
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